

A066393


Coordination sequence for (9^3, 3.9^2) net with respect to a vertex of type 9^3.


2



1, 3, 6, 6, 12, 15, 12, 21, 24, 18, 30, 33, 24, 39, 42, 30, 48, 51, 36, 57, 60, 42, 66, 69, 48, 75, 78, 54, 84, 87, 60, 93, 96, 66, 102, 105, 72, 111, 114, 78, 120, 123, 84, 129, 132, 90, 138, 141, 96, 147, 150, 102, 156, 159, 108, 165, 168, 114
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OFFSET

0,2


COMMENTS

This net may be regarded as a tiling of the plane by 9gons and triangles. There are two kinds of vertices: (a) 9^3 vertices, where three 9gons meet, and (b) 3.9^2 vertices, where a triangle and two 9gons meet. The present sequence is the coordination sequence with respect to a vertex of type 9^3. See also A319980.


REFERENCES

Eon, JeanGuillaume. "Geometrical relationships between nets mapped on isomorphic quotient graphs: examples." Journal of Solid State Chemistry 138.1 (1998): 5565. See Fig. 1.


LINKS

Muniru A Asiru, Table of n, a(n) for n = 0..300
JeanGuillaume Eon, Algebraic determination of generating functions for coordination sequences in crystal structures, Acta Cryst. A58 (2002), 4753. See Section 8.
N. J. A. Sloane, A portion of the (9^3, 3.9^2) net


FORMULA

G.f.: (1+3*x+6*x^2+4*x^3+6*x^4+3*x^5+x^6)/(1x^3)^2.


MAPLE

seq(coeftayl((1+3*x+6*x^2+4*x^3+6*x^4+3*x^5+x^6)/(1x^3)^2, x = 0, k), k=0..60); # Muniru A Asiru, Feb 13 2018


CROSSREFS

Cf. A319980.
Sequence in context: A232941 A080866 A310131 * A127777 A307204 A208445
Adjacent sequences: A066390 A066391 A066392 * A066394 A066395 A066396


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Dec 24 2001


STATUS

approved



